All Questions
Tagged with refraction electromagnetic-radiation
186
questions
66
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4
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What's the physics behind XKCD #2027 (time between lightning flash and radio wave burst)?
XKCD usually has solid (and often contemporary) science behind it. Lightning Difference, #2027 one says:
Q: What’s that trick for telling how many miles away lightning is?
A: Just count the seconds ...
- 6,273
61
votes
4
answers
32k
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Why do prisms work (why is refraction frequency dependent)?
It is well known that a prism can "split light" by separating different frequencies of light:
Many sources state that the reason this happens is that the index of refraction is different for ...
- 12k
56
votes
4
answers
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Do rainbows have ultraviolet bands and infrared bands?
We have seen that rainbows looks so colorful as we are only able to see only the visible light. But Do they also have ultraviolet bands and infra-red bands, that we are unable to see?
I know someone ...
- 1,840
45
votes
3
answers
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How does light re-accelerate after slowing down? [duplicate]
Light travels at speed x through a vacuum, and then it encounters a physical medium and slows down, only to leave the physical medium and re-enter vacuum. The speed of light immediately re-accelerates ...
- 411
41
votes
4
answers
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Why does wavelength change as light enters a different medium?
When light waves enter a medium of higher refractive index than the previous, why is it that:
Its wavelength decreases?
The frequency of it has to stay the same?
- 4,607
23
votes
1
answer
1k
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How can my window not scramble the image of my yard?
How can an image pass through a window if the atoms in the glass randomly emit photons in any direction?
I've read that glass is transparent because the atoms don't readily adsorb visible light, so it ...
- 2,613
18
votes
7
answers
26k
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Why does light change direction when it travels through glass?
This was explained to me many years ago, by a physics teacher, with the following analogy:
"If someone on the beach wants to reach someone else that is in the water, they will try to travel as much ...
- 281
17
votes
5
answers
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Do colors differ in terms of speed? [duplicate]
Here is a very simple question about light. As far as I remember from the school program, each color is merely one of the frequencies of light. I also remember that each color's wave length is ...
- 665
17
votes
1
answer
2k
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Why is not everything transparent? [duplicate]
There is a related question on this site here: Why glass is transparent? Which explains that glass is transparent because the atoms in glass have very large energy differences between energy levels ...
- 562
16
votes
4
answers
3k
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To what extent can speed of light be reduced? [duplicate]
Light slows down upon entering different transparent objects, and the ratio is taken as refractive index of the object. If light can be slowed down, then is there a limit up to which it can be slowed ...
- 803
15
votes
6
answers
6k
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Why are red and blue light refracted differently if they travel at the same speed in the same medium?
When I look at Snell's law
$\frac{\sin\theta_2}{\sin\theta_1} = \frac{v_2}{v_1} = \frac{n_1}{n_2}$
I don't see any reference to wavelength.
If red and blue have the same speed in the same medium, why ...
15
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6
answers
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Why color depends on frequency and not on wavelength? [duplicate]
To explain my question lets consider this example:
The wavelength of light in a medium is $\lambda=\lambda_{0}/\mu$, where $\lambda_{0}$ is the wavelength in vacuum. A beam of red light ($\lambda_{0}=...
- 2,517
15
votes
3
answers
2k
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Can the speed of light become complex inside a metamaterial?
The speed of light in a material is defined as $c = \frac{1}{\sqrt{\epsilon \mu}}$. There are metamaterials with negative permittivity $\epsilon < 0$ and permeability $\mu < 0$ at the same time. ...
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13
votes
5
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Does light change phase on refraction?
I have seen a lot about when light undergoes a phase change when it is reflected. But does it undergo a phase change when refracted and if so why and if not why not?
user43487
13
votes
1
answer
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Why does the refractive index depend on wavelength? [duplicate]
Why do different wavelength get impeded more or less when in different materials? Moving with the same speed, but a longer physical distance would imply that the fields oscillate less times in the ...
user24082